1. Field of the Invention
This invention pertains to homogenization of light sources. More particularly, this invention pertains to a homogenizer which destructures and shapes light.
2. Description of the Prior Art
Prior art diffusers or homogenizers scatter light in various directions, and the intensity in a particular direction depends on the diffuser structure. There are numerous types of conventional diffusers such as ground glass, opal glass, opaque plastics, chemically etched plastics, and machined plastics. Cloth and nylon diffusers are used as well. All of these prior art diffusers have shortcomings that make them unsuitable for many applications. Transmission efficiency is poor, and it is not possible to control the direction, or shape, of diffused light with most of these diffusers.
Lenticular, or machined plastic diffusers, can be made to control the angle of diffused light by varying the characteristics of the surface structures on the diffuser. In this sense, lenticular diffusers are more capable than most other conventional diffusers because, at least, the angle of diffused light can be partially controlled. Nonetheless, lenticular diffusers are undesirable in many applications because they are extremely complex macro-sized, two-sided structures. This makes them difficult and expensive to produce and not well adapted for very high resolution applications. Also, they generate significant side lobes which means that, even if the angle of diffused light can be controlled, much of the light energy is lost in the side lobes and is not transmitted through the desired aperture. Consequently, brightness suffers and higher intensity sources must be used to compensate for these losses.